1. Field of the Invention
The present invention relates generally to a semiconductor process, and more specifically to a semiconductor process planarizing a dielectric layer by treating a shrinkable layer covering the dielectric layer.
2. Description of the Prior Art
In the semiconductor industry, chemical mechanical polishing (CMP) is the most common and important planarization tool applied. For example, CMP processes have been widely adopted in shallow trench isolation (STI) processes or copper (Cu) interconnection etc.
Generally, the CMP process can be used to remove a topographical target of a thin film layer on a semiconductor wafer and to produce a wafer with both a regular and planar surface. In a CMP process, slurry is provided in a surface subject to planarization, and a mechanical polishing process is performed on the surface of the wafer. The slurry includes chemical agents and abrasives. The chemical agents may be PH buffers, oxidants, surfactants or the like, and the abrasives may be silica, alumina, zirconium oxide, or the like. The chemical reactions evoked by the chemical agents and the abrasion between the wafer, the abrasives, and the polishing pad can planarize the surface of the wafer.